Method of preparing dry cleaning compositions



METHOD OF PREPARING DRY CLEANING COMPOSITIONS Martin B. Mathews,Chicago, and Charles E. Stautfer, River Forest, 111., assignors to R. R.Street & Co., Inc., Chicago, 111., a corporation of Illinois No Drawing.Application October 29, 1952, Serial No. 317,571

9 Claims. (Cl. 252-161) Our invention relates to the cleaning ordetergent field, and, more especially, the dry cleaning field, and isparticularly concerned with new and improved methods of simply anddirectly producing compositions containing, as essential ingredientsthereof, an inert high boiling organic liquid solvent having a boilingpoint or an initial boiling point not substantially below 200 degrees C.in which are dissolved certain oil-soluble esters of sulfopolycarboxylicacids, said compositions being substantially free of inorganic saltsand, preferably, also being substantially free from water as prepared.

The compositions of matter which are prepared in accordance with ourpresent invention are highly useful, among other purposes, as drycleaning detergents and dry cleaning emulsifying agents and are adaptedto be admixed with hydrocarbons, chlorinated hydrocarbons, and otherorganic solvents. They are highly effective in the production ofemulsion wherein the external phase is an organic water-insolubleliquid, the internal phase being water or aqueous material or otherliquids which are insoluble in the organic phase. In order to be fullyeffective for use in the dry cleaning field, it is important that suchcompositions be substantially free of inorganic salts, generally belowabout 0.1% by weight, and it is also highly desirable, at least in mostcase, that, as prepared, they be substantially free of water.

Oil-soluble esters of sulfopolycarboxylic acids are, per se, not new,being shown, for instance, in U. S. Patents Nos. 2,028,091; 2,176,423;2,315,375 and 2,345,041. Moreover, they have heretofore been disclosedfor use in dry cleaning liquid organic solvents as well as inconjunction with paraflin oils or parafiin hydrocarbons. Said estershave heretofore been prepared, for example, by reacting a maleic acidalcohol diester, for example, dicaprylmaleate, with .sodium bisulfite inan aqueous medium. The resulting reaction mixture is then dried and,where it is desired that said mixture be free of inorganic salts, thishas been accomplished by dissolving the reaction mixture in an organicsolvent such as benzene, filtering, and evaporating the benzene. Thisprocedure is a costly and cumbersome one in that it requires, amongother things, the preliminary drying of the reaction mixture and this,in itself, presents a number of difliculties because various of thesulfopolycarboxylic acid esters are of a gummy nature and presentserious problems with respect to the handling and drying thereof.

In accordance with our invention, compositions having marked efficacy inthe dry cleaning field, which compositions contain an inert high boilingorganic liquid solvent having a boiling point or an initial boilingpoint not substantially below 200 degrees C., in which are dissolvedoil-soluble esters of sulfopolycarboxylic acids, are prepared in such amanner as to offer marked advantages over earlier methods heretoforesuggested. As indicated, the compositions are directly prepared in aform wherein they are-readily adapted for use in the dry cleaning fieldand form highly useful dry cleaning compositions. When added in smallamounts to dry cleaning water-immiscible Patented Mar. 12, 1957 organicsolvents, such as naphtha, Stoddard solvent, carbon tetrachloride,trichlorethylene, benzene, gasoline, and the like, they enablesubstantial amounts of water to be taken up by the organic solvents andlargely retain such water during the dry cleaning operation, the waterbeing so finely dispersed in the organic solvent that the clarity of thelatter is not visibly afiected.

In the practice of our invention, the inorganic salts and moisture areremoved after the reaction is essentially completed without requiringthe handling of the product in the form of a solid or semi-solid gummymass and without requiring expensive drying operations followed byextraction with organic solvents. By proceeding in accordance with ourinvention, these latter expensive and cumbersome steps are avoided and,at the same time, reduction of the inorganic salt content in the finalproduct to the desired degree is readily effected in an inexpensive andsimple manner.

In the practice of our invention, an alcohol ester of an unsaturatedpolycarboxylic acid, for example, lauryl fumarate, is reacted with analkali bisulfite, particularly sodiumbisulfite, in the presence of waterand in the additional presence of an inert high boiling organic liquidsolvent, for example, a petroleum hydrocarbon fraction having an initialboiling point, at atmospheric pressure, not substantially below 200degrees C., such fraction being exemplified by a mineral oil having aninitial boiling point of the order of 200 to 220 degrees C. or more. Ingeneral, we prefer to utilize petroleum fractions having a boiling pointrange, at atmospheric pressure, between about 200 and 400 degrees C. or,still more preferably, between about 260 and 350 degrees C. Other highboiling organic liquid solvents include esters of the type which arecommonly used as plasticizers, polyglycols, etc. which are inert underthe conditions of the reaction. The mixture is reacted, under conditionsof agitation, at somewhat elevated temperatures, usually of the order ofdegrees C. to somewhat in excess of degrees C. until the reaction isessentially completed, that is, the production of thesulfopolycarboxylic acid ester is achieved. This usually takes at leastseveral hours. It is preferred to carry out the reaction'at atomsphericpressure but, if desired, the reaction can be performed at greaterpressures in which event the reaction conditions may be somewhatmodified. The mineral oil or other inert high boiling organic liquidsolvent serves, among other things, to maintain the reaction mixture ina state where it can be handled as a liquid, particularly toward the endof the reaction Where, if it were not present, a gummy reaction mixturewould usually result which could not be stirred or satisfactorilyhandled.

At the completion of the reaction, there is then particularlyadvantageously added to the reaction mixture 21 further quantity of amineral oil or similar petroleum fraction or the like having an initialboiling point not substantially below 200 degrees C. and, in addition,it, is especially desirable to add a volatile organic solvent which isdistillable together with water to assist in the subsequent eliminationof water from the mixture. Typical examples of such latter agents arecarbon tetrachloride, trichlorethylene, benzene, perchlorethylene, andtoluene. The mixture is then heated to distill therefrom water and theadded volatile organic solvent. In the usual case, the temperature towhich the mixture is heated to effect removal of water and organicsolvent will fall Within the range of about to about degrees C.Thereafter, to the residual mass it is particularly desirable to add apetroleum fraction having an initial boiling point not substantiallybelow 200 degrees C., for example, a mineral oil, or a volatile organicsolvent such as Stoddard solvent, trichlorethylene or benzene or thelike, after which the mixture is cooled and filtered. The final productis a isu iifim. t tstant allx reapt .in r aa asdo.ant

au yl su q u cinete. 21. usu l. ase, Wc., fi '1d; tTPar-:

ticularly satisfactory to, produce compositionspcontaining about;40% toabout 65 preferably about 55 to 60%,

weight, of the esters of sulfopolycarboxylic,acidsin the mineraloil orlike or'other petroleum hydrocarbon fraction. V p v For particularlyelfectiye'use in the dry cleaning industry, in connection withtheproduction of oil-soluble e en n a h rm t on. Qf: t -.in-oi1 emu sio s,the alcohol radical of the sulfosuccinic acid esters should, be ofaliphatic character. and contain; from 6-toabout 10 carbon atoms. Forothendetergent and allied uses, the

alcohol maybe of aromatic or hydroaromatic oraromatic aliphaticcharacter and may contain up to 22 but preferably from Sto 18 carbonatoms. Typical examples of such alcohols are, therefore, n l1exyl.alcohol, ,isohexyl.

alcohol, n-heptyl alcohol, n-octyl alcohol, Z-ethylhex'yl alcohol,mixtures of dimethyl hexanols, n nonyl alcohol,

isononyl alcohol, isomeric nonyl alcohols, decylalcohol, undecylalcohol, dodecyl alcohol, tetradecyl alcohol, cetyl alcohol, oleylalcohol, stearyl alcohol, cyclohexanol, phenylethyl alcohol, benzylalcohol,cresols,:jnaphthols,

etc. Reference may be had, for example, to the afore-..

mentioned patents for other alcohols whose esters withsulfopolycarboxylic aids are oil-soluble; It will be understood thatmixtures of anytwo or more of suchalcohols can also effectively beutilized, Those of the esterswhich.

are utilized in accordance with the present invention are, as'pointedout above, the sulfopolycarboxylic acid esters inwhich one or all of thecarboxyl groups of the polycarboxylic acid are esterified with theaforesaid alcohols. While, in the usual case, where all of the carboxylgroups of the sulfopolycarboxylic acid are esterified they'will be.

esterified with the same alcohol or alcohols, it will be understood thatthe production -of compositions within the scope 'of our. invention alsocomprises such mixed esters wherein, for instance, one of the carboxylgroups may be esterified with, for example,.one aliphatic alcohol suchas hexyl alcohol, and the, other or others of the carboxyl groups may beesterified with another aliphatic alcohol such as octyl alcohol] Amongthe unsaturated polycarboxylicacids Whose alcohol esters are utilized asone of the reactants in accordance with the present invention are, byway of example,"dicarboxylic acids such as maleic acid (or maleicanhydride'), iumaric acid, glutaconic acid, mesaconic acid,

itaconic' acid, citraconic acid, and tricarboxylicacids such as aconiticacid, and others which may be disclosed, for instance, in theaforementioned patents.

The following examples are illustrative of the practice of ourinvention. It will be understood that these examples are not to beconstrued in any way as limitative of the dull scope of our inventionsince dififerent alcohols oan be utilized, the proportions of theingredients can be varied, the reaction temperatures and times arelikewise variable, within limits, and other modifications can be made,all within the spirit and guiding principles of the teachings herein.All parts stated are by weight.

Example 1 additional'parts of mineral oil is addedand, after cooling toroom temperature, or somewhat therea-bove, the mixture Example 2 Q 300parts of dibenzyl. maleate, prepared by esterification of maleicanhydride with benzyl alcohol, is admixed with 35 partsminer'al oil(initialB. P. 245 degrees C.), 105 parts of water and 105 parts ofsodium bisulfite, and the mix-ture is heated, with agitation, at about100 degrees C. dor about .20 hours. Then additional parts of mineral oiland 90 parts of perchlorethylene are added and the mixture is heated andallowed to distill until the tempera ture of the mixture reaches 180degrees C. To the residual mass, additional parts of mineral oil isadded and, after cooling to. about room temperature, the

mixture is. filtered whereupon a clear composition is ob-.tainedcontaining a.high percentage of sodiurndibenzyl zou a'a's' oftri-n-hexyl aconitate' is admixed with 16 parts mineral oil (initial B.P. 235 degrees C.), 60 parts wa-ter 'and .60 parts sodium bisulfite, andthe mixture is heated, with agitation, at about 100v degrees C. forabout 24 hours whereby sodium trin-hexyl sulfotricarballylate isproduced in the reactionmixture. Then 50 additional parts of mineral oiland 50 parts of perchlorethylene are added and the mixture is heated andallowed to distill until the temperature of the mixture reaches, about185 degrees C. To the residual mass 65 additional parts of mineral oilis added and, after cooling to room temperature or somewhat thereab'ove,the mixture is filtered whereupon a clear composition is obtainedcontaining in excess of 50%, by weight, of sodium tr-i-n-hexylsulfotricarballylate,

mineral oil (initial B. R245 degrees C.), 60 parts of water and 65.parts of ammonium bisulfite, and the mixture is heated, with agitation,at about 100 degrees C. forabout 18 hours. Then 50 additional parts ofmineral oiland'50 parts of perchlorethylene are added and the mixture isheated and allowedto distill until the temperature of the mixturereaches degrees C. To the residual mass, 60 additional parts of mineraloil is added and, after cooling to about room temperature, the mixtureis filtered whereupon a clear composition is obtained containing a highpercentage of ammonium trioctyl sulfotricarballylate, said compositionbeing substantially free of inorganic salts.

Example 5 200 parts of triphenylethyl aconitate is admixed with 20'parts mineraloil (initial B. P. 225 degrees C.), 60 parts water and 6Oparts sodiumbisulfite and the mixture' is heated,with agitation, atabout 100 degrees C. for about 16 hours whereby sodiumtriphenylethylsulfotricarballylate is produced in the reaction mixture.Then 50 additional parts of mineraloil and 50 parts of perchlorethylene'areadded and the mixture is heated and allowed to distilluntilthetemperature of the mixture relation to Example 1, comprises, based onthe use of 320 parts of dilauryl maleate, from about to about 35 partsof mineral oil, from about 80 to about 110 parts of water, and fromabout 80 to about 110 parts of sodium bisulfite in the reaction properto produce the diester of sulfosuccinic acid. A good average reactiontemperature is from about 95 to about 110 degrees C. and a good averagereaction time is from several hours to about 24 hours. The amount ofmineral oil or the like which is added initially after the completion ofsaid reaction is from about 70 to about 100 parts and the amount ofvolatile organic solvent, such as perchlorethylene, utilized willordinarily vary from about 50 to about 150 parts. These illustrativefigures will serve as guides to enable those versed in the art readilyto select suitable operating con ditions and proportions of ingredientsetfectively to carry out the teachings of our invention.

Where reference is made in the claims to the boiling point of the inertorganic liquid solvent, it will be understood to include the initialboiling point of such liquids Where the latter have a boiling pointrange as, for instance, in the case of petroleum hydrocarbons whichcontain mixtures of various fractions.

What we claim as new and desire to protect by Letters Patent of theUnited States is:

l. A method of preparing a dry cleaning composition, which comprisesreacting, under agitation, an alcohol ester of a polycarboxylic acid,the alcohol radical of which contains at least 6 carbon atoms and thepolycarboxylic acid radical of which contains a double bond, with analkali bisulfite in aqueous solution and in a mineral oil having aninitial boiling point not substantially below 200 degrees C., saidpolycarboxylic acid ester and said alkali bisulfite being present inproportions to produce the alkali salt of the sulfopo lycarboxylic acidester of said alcohol, said mineral oil being present in amountssufiicient to maintain the reaction medium in a liquid conditionthroughout said reaction, at the end of said reaction adding to thereaction mixture a liquid volatile organic solvent which is distillabletogether with water at a temperature below 190 degrees C., then heatingthe mixture to remove the water and at least most of the lastmentionedliquid volatile organic solvent but not said mineral oil, and filteringwhereby to obtain a liquid composition substantially free of inorganicsalts.

2. A method of preparing a dry cleaning composition, which comprisesreacting, under agitation, an alcohol ester of a dicarboxylic acid, thealiphatic alcohol radical of which contains from 6 to about 22 carbonatoms and the dicarboxylic acid radical of which contains a double bond,with sodium bisulfite in aqueous solution and in a mineral oil having aboiling point between about 260 and 350 degrees C., said dicarboxylicacid ester and said sodium bisulfite being present in proportions toproduce the sodium salt of the sulfodicarboxylic acid ester of saidalcohol, said mineral oil being present in amounts sufiicient tomaintain the reaction medium in a liquid condition throughout saidreaction, at the end of said reaction adding to the reaction mixture amineral oil having a boiling point between about 260 and 350 degrees C.and also adding a liquid volatile organic solvent which is distillabletogether with water at a temperature below degrees C., then heating themixture to remove the water and at least most of the last-mentionedliquid volatile organic solvent but not said mineral oil, and filteringwhereby to obtain a liquid composition substantially free of inorganicsalts.

3. A method of preparing a dry cleaning composition, which comprisesreacting, under agitation, an alcohol ester of a tricarboxylic acid, thealcohol radical of which contains from 6 to about 22 carbon atoms andthe tricarboxylic acid radical of which contains a double bond, with analkali bisulfite in aqueous solution and in a mineral oil having aninitial boiling point not substantially below 200 degrees C., saidtricarboxylic acid ester and said alkali bisulfite being present inproportions to produce the alkali salt of the sulfotricarboxylic acidester of said alcohol, said mineral oil being present in amountssufficient to maintain the reaction medium in a liquid conditionthroughout said reaction, at the end of said reaction adding to thereaction mixture a liquid volatile organic solvent which is distillabletogether with water at a temperature below 190 degrees C., then heatingthe mixture to remove the water and at least most of the lastmentionedliquid volatile organic solvent but not said mineral oil, cooling theresidual product, and then filtering whereby to obtain a liquidcomposition substantially free of inorganic salts and water.

4. A method in accordance with claim 1, wherein the alcohol isphenylethyl alcohol.

5. A method in accordance with claim 3, wherein the alcohol is oleylalcohol.

6. A method in accordance with claim 3, wherein the tricarboxylic acidis aconitic acid.

7. A method in accordance with claim 6, wherein the alcohol istetradecyl alcohol.

8. A method in accordance with claim 6, wherein the alcohol is laurylalcohol.

9. A method in accordance with claim 6, wherein the alcohol is cetylalcohol.

References Cited in the file of this patent UNITED STATES PATENTS2,028,091 Jaeger Jan. 14, 1936 2,315,375 Nawiasky et al Mar. 30, 19432,327,183 Flett Aug. 17, 1943

1. A METHOD OF PREPARING A DRY CLEANING COMPOSITION, WHICH COMPRISESREACTING, UNDER AGITATION, AN ALCOHOL ESTER OF A POLYCARBOXYLIC ACID,THE ALCOHOL RADICAL OF WHICH CONTAIN AT LEAST 6 CARBON ATOMS AND THEPOLYCARBOXYLIC ACID RADICAL OF WHICH CONTAIN A DOUBLE BOND, WITH ANALKALI BISULFITE IN AQUEOUS SOLUTION AND IN A MINERAL OIL HAVING ANINITIAL BOILING POINT NOT SUBSTANTIALLY BELOW 200 DEGREES C., SAIDPOLYCARBOXYLIC ACID ESTER AND SAID ALKALI BISULFITE BEING PRESENT INPROPORTIONS TO PRODUCE THE ALKALI SALT OF THE SULFOPOLYCARBOXYLIC ACIDESTER OF SAID ALCOHOL, SAID MINERAL OIL BEING PRESENT IN AMOUNTSSUFFICIENT TO MAINTAIN THE REACTION MEDIUM IN A LIQUID CONDITIONTHROUGHTOUT SAID REACTION, AT THE END OF SAID REACTION ADDING TO THEREACTION MIXTURE A LIQUID VOLATILE ORGANIC SOLVENT WHICH IS DISTILLABLETOGETHER WITH WATER AT A TEMPERATURE BELOW 190 DEGREES C., THEN HEATINGTHE MIXTURE TO REMOVE THE WATER AND AT LEAST THE LASTMENTIONED LIQUIDVOLATILE ORGANIC SOLVENT BUT NOT SAID MINERAL OIL, AND FILTERING WHEREBYTO OBTAIN A LIQUID COMPOSITION SUBSTANTIALLY FREE OF INORGANIC SALTS.